Soils and Foundations最新文献

{"title":"Macroscale and microscale triaxial compressive behaviors of loose saturated sand under excess pore water pressure generation","authors":"Ryunosuke Kido ,&nbsp;Yuya Ohtani ,&nbsp;Yosuke Higo","doi":"10.1016/j.sandf.2025.101725","DOIUrl":"10.1016/j.sandf.2025.101725","url":null,"abstract":"<div><div>Investigating the triaxial compressive behavior of loose saturated sand under excess pore water pressure generation, based on both macroscale and microscale observations, contributes to a better understanding of the instability mechanisms associated with the non-localized failure mode. In this study, the original intention was to conduct undrained triaxial tests on dense and loose saturated sands. However, due to the unavoidable limitations associated with X-ray CT imaging, the tests were consequently conducted under a partially drained condition. Nevertheless, the use of X-ray CT imaging, combined with image analyses, revealed clear differences in both the macroscopic responses and microscale structural evolution between dense and loose saturated sands that exhibit localized and non-localized failure modes. The loose sand examined in the present study showed a gradual increase in deviator stress until the end of shearing. During this process, the local void ratio gently decreased and the number of particle contacts gently increased due to compression. The particle-contact orientation did not change significantly from the initial state to the end of shearing. Shear strain was found to be relatively uniformly distributed over a wide region in the loose sand specimens. It is likely that these deformation characteristics of loose sand correspond to positive second-order work, indicating the stable state of the material. This behavior was clearly different from that of the dense sand specimens, for which significant dilation, a decrease in the number of particle contacts, and a change in the particle-contact orientation that occurred, were associated with a localized failure mode characterized by negative second-order work.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101725"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the liquefaction resistance and initial shear modulus of silty sands from equivalent intergranular void ratio concept","authors":"F. Shi ,&nbsp;H. Kaneko ,&nbsp;M. Maeda ,&nbsp;T. Ishimaru ,&nbsp;Y. Tsukamoto","doi":"10.1016/j.sandf.2025.101726","DOIUrl":"10.1016/j.sandf.2025.101726","url":null,"abstract":"<div><div>Multiple series of laboratory undrained cyclic triaxial tests and bender element tests are conducted to obtain pairing data for <em>R</em>_l and <em>G</em>_o for laboratory reconstituted samples of silty sands. Several categories of silty sands in a ‘fines in sand’ matrix are prepared using coarse, medium, and fine sands as the host sands and non-plastic fines with different fines contents of <em>F</em>_c = 0–30% as the guest silt. The concept of the equivalent intergranular void ratio is that it is used to deduce the <em>b</em>-values for <em>R</em>_l and <em>G</em>_o. Instead of applying the empirical expression, as employed in past studies, the <em>b</em>-values are determined by directly fitting the silty sand data to the corresponding backbone clean sand relation. The fictitious active fines content, defined as <em>F</em>_c* = <em>bF</em>_c, is then introduced, which bears a good physical meaning for mechanical interpretations of the test results. <em>F</em>_c* tends to increase rapidly as <em>F</em>_c increases, following the empirical expression of <em>F</em>_c* = <em>μF</em>_c². The corresponding values for <em>F</em>_c.l* and <em>F</em>_c.s* for large-strain <em>R</em>_l and small-strain <em>G</em>_o, respectively, are directly compared. It is found that they take different values, and that the ratio of <em>F</em>_c.l*/<em>F</em>_c.s* is dependent on the size disparity ratio for <em>χ</em> and <em>F</em>_c. The implications of this experimental finding are discussed with respect to the micromechanical modelling of the silty sand behaviour. The differences in the values for <em>F</em>_c.l* and <em>F</em>_c.s* are found to lead to multiple series of cyclic resistance ratio CRR and shear wave velocity <em>V</em>_s relations for silty sands with different <em>F</em>_c, which are comparable to the empirical relations given in past studies.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101726"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical insight into twin tunnelling-induced soil-structure interaction in battered pile-supported systems under lateral loading","authors":"Mukhtiar Ali Soomro,&nbsp;Sharafat Ali Darban","doi":"10.1016/j.sandf.2026.101747","DOIUrl":"10.1016/j.sandf.2026.101747","url":null,"abstract":"<div><div>With rapid increasing urbanization, the construction of twin tunnels adjacent to existing foundations has become common in underground development projects. This study investigates the influence of twin parallel tunnelling on elevated battered pile group and battered piled raft subjected to lateral loading in soft clay. A series of three-dimensional coupled consolidation finite element analyses, incorporating an advanced hypoplastic clay model with small-strain stiffness are carried out. The model parameters are validated using centrifuge test data to ensure realistic simulation of tunnelling-induced ground deformations. Twin tunnels are positioned at varying depths relative to the battered piled foundation: neat the shaft, near the toe, and below the toe of the piles. Results reveal that the largest lateral displacements and differential settlements occur when tunnelling is near the pile toe. The second tunnel further increases movement toward the first tunnel due to degraded ground stiffness. Compared to elevated battered pile groups, battered piled rafts exhibit significantly reduced lateral displacements, deflections, and settlements because of additional resistance from raft-soil interaction. Twin tunnelling in each case also alters axial load distribution. Twin tunnelling near pile shaft caused reduction of 61% in shaft resistance whereas 20% of end-bearing decreased in twin tunnelling near pile toe. The maximum bending moments were induced near the pile head in battered elevated pile group but are smaller in piled rafts (up to 30% reduction) in each case.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101747"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polyacrylamide improves the strength of peat soil while reducing cement consumption: An experimental and machine learning investigation","authors":"Yangshou Yu ,&nbsp;Zhiliang Wang ,&nbsp;Miao Li ,&nbsp;Lei Lang ,&nbsp;Linfang Shen ,&nbsp;Yang Yu","doi":"10.1016/j.sandf.2026.101745","DOIUrl":"10.1016/j.sandf.2026.101745","url":null,"abstract":"<div><div>Peat soil presents poor geotechnical properties, posing significant risks to structural stability when used as a foundation material. This study investigates the potential of polyacrylamide (PAM) as an adhesive additive to enhance the strength of peat soil stabilized with cement and sand. Unconfined compressive strength (UCS) tests were conducted to evaluate PAM’s effectiveness, complemented by microscopic analyses to explore underlying improvement mechanisms. Results show that PAM significantly increases soil strength, with higher PAM content yielding greater gains. Specifically, adding 10 % PAM boosts the UCS of untreated peat soil by up to 2.5 times and improves the strength of peat soil treated with 30 % cement and 30 % sand by 174.1 kPa. PAM also reduces soil permeability without exhibiting ecotoxicity. Microscopic observations reveal that PAM forms cross-linked gel networks that bind soil particles into large aggregates. 10 % PAM decreases the specific surface area, pore volume, and average pore size by 32.6 %, 42.2 %, and 21.4 %, respectively. Importantly, PAM does not alter the chemical composition of the stabilized soil and remains stable over time. Finally, a gene expression programming (GEP) algorithm was used to develop a predictive mathematical model for UCS, achieving a coefficient of determination (<em>R</em>²) above 0.97. An analysis of cement consumption using this model indicates that incorporating 10 % PAM can reduce cement consumption by 26.1 % to achieve a target strength of 300 kPa, compared with using only cement and sand. These findings demonstrate that PAM is an effective and environmentally beneficial stabilizer for peat soil.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101745"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the relationship between freezing point and suction of sodium sulfate loess near 0°C","authors":"Songhe Wang ,&nbsp;Yang Wang ,&nbsp;Yuhang Liu ,&nbsp;Jiading Wang ,&nbsp;Jiulong Ding ,&nbsp;Xiaoliang Yao","doi":"10.1016/j.sandf.2026.101753","DOIUrl":"10.1016/j.sandf.2026.101753","url":null,"abstract":"<div><div>Correlation between freezing point and suction of sodium sulfate loess upon phase change is fundamental for understanding the mechanism of salt weathering of check dams in Loess Plateau of China. Given the ongoing controversies over frozen soil suction measurement, soil suction test near 0°C was employed as a compromise to link with freezing point. The test data from vapor equilibrium technique (VET) and the TEROS-21 Gen 2 soil water potential sensor were combined with the reported data to derive a temperature-dependent calibration model from the correspondence between the suction and the equilibrium water content of Whatman No. 42 filter paper. This model holds the merits of robust accuracy, simple structure with merely two parameters to be calibrated, and the capacity to capture the temperature effect on the calibration curve. The freezing point of sodium sulfate loess is closely linked to the suction at 0.5°C. Both matric and osmotic suctions do not linearly superimpose on the freezing point but exhibit a coupling effect. A modified Mizoguchi model was accordingly developed and verified for five types of saline loess. The results will throw light on the nature of salt weathering of check dams and are also encouraging for targeted treatments.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101753"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Special issue on climate change adaptation and innovation from geotechnical perspectives","authors":"Hemanta Hazarika (Guest Editor)","doi":"10.1016/j.sandf.2026.101744","DOIUrl":"10.1016/j.sandf.2026.101744","url":null,"abstract":"","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101744"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Failure area change estimation and tunnel face pressure characteristics of large soil-covering tunnel tests","authors":"Ryo Kawanoue ,&nbsp;Yota Togashi ,&nbsp;Masahiko Osada ,&nbsp;Jiro Kuwano","doi":"10.1016/j.sandf.2025.101723","DOIUrl":"10.1016/j.sandf.2025.101723","url":null,"abstract":"<div><div>Estimating the tunnel face earth pressure is essential for determining the limit support pressure in shield tunneling and for urban mountain tunnels in Japan. To meet these demands, limit equilibrium methods for calculating tunnel face pressures remain extremely important methods of calculation in tunneling practice. In limit equilibrium calculations, the appropriate setting of the failure zone prism affects the accuracy. It is crucial to properly account for changes in the height of the failure zone prism due to the frictional resistance of the ground. In this study, an improved simple method is proposed for estimating the height of the failure zone prism. The method utilizes a versatile logistic equation to describe the relationship between the soil cover and the prism height. The proposed method is a model in which the height of the failure zone prism converges to a constant value in the logistic equation as the soil cover increases, indicating an increase in frictional resistance. To validate the proposed method, tunnel tests with large soil cover ratios up to <span><math><mrow><mi>C</mi><mo>/</mo><mi>D</mi><mo>=</mo><mn>10</mn></mrow></math></span> in a 1 g field are conducted, and changes in the failure zone prism and the nature of the soil pressure are determined. As a result of the tunnel tests, the width of the failure zone can be approximately expressed by the width of the wedge derived under the condition of active earth pressure. The face pressure at the initial stage of tunnel pulling in the tunnel tests is proportional to the soil cover pressure when the soil cover is small. On the other hand, as the soil cover increases, it shows a value between the earth pressure at rest and the active earth pressure. This is thought to be due to the fact that the frictional resistance of the ground increases in proportion to the soil cover. Furthermore, the height of the failure zone prism, identified by a PIV (particle image velocimetry) analysis, can be adequately represented by the proposed method. An example of how the proposed equation can be incorporated into a simple limit equilibrium calculation is described, and it is shown that the results of this calculation can properly evaluate the experimental results.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101723"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of gradation characteristics on seepage failure in foam-conditioned gap-graded soils for EPB shield tunneling","authors":"Bin Wang ,&nbsp;Shuying Wang ,&nbsp;Xiangcou Zheng ,&nbsp;Xinggao Li ,&nbsp;Fei Ye","doi":"10.1016/j.sandf.2026.101748","DOIUrl":"10.1016/j.sandf.2026.101748","url":null,"abstract":"<div><div>Muck spewing at the screw conveyor outlet in water-rich coarse-grained soils poses a significant risk to the efficiency and safety of shield tunneling. This study systematically investigates the influence of gradation characteristics on the seepage failure behavior of foam-conditioned gap-graded soils through vertical upward hydraulic tests. The effects of fines content, gap ratio, and foam injection ratio on failure modes and hydraulic responses are examined. Results show that the seepage failure mode is jointly controlled by the combined effects of particle size distribution, fines content, and foam injection. Changes in the gap ratio can trigger transitions between piping and heave failure, and excessively high foam injection can destabilize soil during heave. The pore structure, regulated by gradation, determines the stability of foam within the soil, with a sufficient proportion of fine particles essential for maintaining internal stability and mitigating seepage erosion. These findings provide insights into the mechanisms by which gradation characteristics influence seepage failure and offer guidance for foam conditioning practices in shield tunneling, supporting the theoretical modeling of critical hydraulic gradients in foam-conditioned soils.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101748"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and numerical study on dynamic responses of three-story building supported by T-BAGS base isolation and vibration control system","authors":"Ali Vakilazadsarabi ,&nbsp;Kinji Takeuchi ,&nbsp;Yasuo Tomono ,&nbsp;Tatsunori Matsumoto","doi":"10.1016/j.sandf.2026.101741","DOIUrl":"10.1016/j.sandf.2026.101741","url":null,"abstract":"<div><div>T-BAGS is a seismic base isolation and vibration control system. It is composed of two stacked layers of geotextile sandbags filled with sand. A slip sheet is sandwiched between the upper and lower sandbags to control the slippage between them. Slipping between the upper and lower sandbags works as base isolation. Furthermore, the hysteretic shear deformation of each sandbag plays a role in vibration control. In this research, the static and dynamic behaviors of the T-BAGS system are firstly investigated through laboratory tests, including simple shear tests on one sandbag and shaking table tests on six sets of T-BAGS. Then, dynamic numerical analyses of the shaking table tests are conducted. Based on the results, dynamic 3D analyses of a 3-story residential RC building, subjected to a severe earthquake, are conducted with and without the T-BAGS system. The building and the T-BAGS system are integrated and modeled as a three-dimensional series of masses and nonlinear springs. In those numerical analyses, the influence of the rigidity of the sandbags on the dynamic behaviors of the building is investigated. The results indicate that the response acceleration of the building, induced by the severe earthquake, could be considerably attenuated through the use of the T-BAGS base isolation and vibration control system. It is emphasized that the hysteretic shear behavior of the sandbags contributes significantly to vibration control.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101741"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sustainable soil improvement using marine-derived biopolymers: strength and durability perspectives","authors":"Runshen Wang ,&nbsp;Hadi Fatehi ,&nbsp;Dominic E.L. Ong ,&nbsp;Jimmy Yu ,&nbsp;Ilhan Chang ,&nbsp;Khosro Shabani","doi":"10.1016/j.sandf.2026.101730","DOIUrl":"10.1016/j.sandf.2026.101730","url":null,"abstract":"<div><div>This study provides a comprehensive evaluation of marine biopolymers for sustainable soil stabilization. It offers critical insights for countries with abundant ocean resources to support the selection of suitable biopolymer for soil enhancement. The experimental program covers a wide range of mechanical and microstructural evaluations to support a broad understanding of biopolymer-treated soil behaviour. A range of marine biopolymers was tested with a specific focus on chitosan due to its distinct structure and bonding capability. The study focused on engineered kaolinite-sand mixtures, selected for their ability to represent complex and variable soil conditions commonly encountered in the field. Experimental variables such as biopolymer content, curing time, and soil composition were systematically controlled. Mechanical properties were assessed using UCS, and static and dynamic triaxial tests to determine shear strength and resilient modulus. Durability was assessed through five cycles of wetting and drying to replicate long-term environmental exposure. Results showed that biopolymer content and soil type significantly influenced strength development and water resistance. Chitosan achieved up to a tenfold increase in UCS, with substantial strength retention and low mass loss under cyclic conditions. Microstructural analysis using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) provided insights into the chemical bonding and physical interactions at the soil–biopolymer interface. A mechanical model was proposed to explain these interactions. Overall, the study demonstrates the potential of marine biopolymers as effective, ecofriendly alternatives to traditional chemical stabilizers, offering a sustainable solution for geotechnical engineering applications.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101730"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}